Biomedical subjects

N Yashiro

Publications and source records attributed to N Yashiro.

118 records · Page 7Linked to original sources

PubMedDate not supplied

Magnetic resonance of liver tumors: a preliminary report.

Early experience in magnetic resonance (MR) images of the liver tumors is reported, based on 25 cases examined by a 0.35T superconducting machine (Magnetom, Siemens) using the spin echo technique. All main liver tumors were demonstrated as high intensity areas of varying degree in the spin echo image with a TR of 1,600 msec and a TE of 70 msec. All of them had prolonged T2 and T1. The smallest lesion detected on MR was 0.8 cm in diameter in the cases of multiple liver cysts and 1.5 cm in the cases of a solitary solid tumor. Normal vasculature of the liver was well-delineated, despite a far longer acquisition time compared with respiratory holding period. MR is a promising modality for liver imaging.

Carcinoma, Hepatocellular↗

PubMedDate not supplied

Intraarterial digital subtraction portography in patients with liver tumors.

Intraarterial digital subtraction portography (IADSP) via the superior mesenteric artery was performed in 50 patients with liver tumors. In most cases IADSPs provided images as good as conventional arterial portography through the superior mesenteric artery and they produced important information as to whether patients should be treated by transcatheter arterial embolization, surgical resection or chemotherapy. IADSP helps to reduce the examination time, the number of films and contrast material used, as well as the pain suffered by patients.

Humans↗

PubMedDate not supplied

Intraarterial digital subtraction angiography of peripheral arteries with isotonic contrast material.

Intraarterial digital subtraction angiography (IADSA) of peripheral arteries with isotonic contrast material, which was prepared by diluting meglumine amidotrizoate (65% Angiografin), was performed in ten patients. In six, both IADSA and conventional screen-film arteriography were performed for comparison. Painless peripheral arteriography was achieved by IADSA with isotonic contrast material. Five IADSAs were safely done on an outpatient basis. Visualization of arteries by IADSA was satisfactory, but the details of smaller arteries were better shown by screen-film arteriography. Visualization of faint stains was better in IADSA. The authors believe that IADSA with isotonic contrast material is a method of choice for the diagnosis of vascular diseases and tumorous conditions of extremities, as well as for the purpose of preoperative vascular mapping. It is safely performed with smaller dose of contrast material on outpatient basis, and with less discomfort and cost for the patient.

Angiography↗

PubMedDate not supplied

Bilateral synchronous renal cancer.

Six cases of concurrent bilateral renal cancer are reported. These cases represented 3.7% of 163 renal cancers in our institute during the period 1965-1983. Five of the six cases were examined by CT. One earlier case received only selective renal arteriography. Three patients who had extrarenal metastases at the initial presentation showed poor prognoses and died within a year. The other three showed better prognoses. One had bilateral multiple renal cell cancer which was not associated with von Hippel-Lindau disease. One survived 4.5 years after unilateral nephrectomy and chemotherapy. One received unilateral total embolization combined with partial embolization of the contralateral kidney and is still well 1.5 years after initial diagnosis, without evidence of remote metastases. The smaller tumors of bilateral renal cancer were early in stage and were detected by CT. CT is thought to be the best method for detecting small asymptomatic tumors amenable to conservative surgery. Angiography is thought to be essential for the planning of embolization and partial nephrectomy. Although it is an interesting question whether each tumor has a multicentric origin or whether one is a metastasis of another, no criteria seem to exist which are completely satisfactory for making this distinction.

Aged↗

PubMedDate not supplied

Internal jugular phlebectasia in children.

Two pediatric cases with internal jugular phlebectasia which showed specific clinical and radiographic features are described. CT and venography were useful in the diagnosis. Differential diagnosis of cervical masses which enlarge with Valsalva maneuver are also discussed with a review of the literature.

Child↗

PubMedDate not supplied

Adult adrenal neuroblastoma with extension into inferior vena cava.

An adult left adrenal neuroblastoma that extended into the left renal vein and inferior vena cava is reported. To the best of our knowledge, venous involvement of adrenal tumors has been reported in adrenal cortical carcinomas, but not in neuroblastomas. Differentiation of renal and adrenal tumors is also discussed.

Adrenal Gland Neoplasms↗

PubMedDate not supplied

Intraarterial digital subtraction arteriography in the management of renal tumors.

Nine patients with renal tumors were studied by intraarterial digital subtraction arteriography (IADSA). Embolization was performed in six patients. IADSA was evaluated on the following practical points: vascular mapping, renal vein visualization, and embolization. Vascular mapping by IADSA was satisfactory in eight patients. The limitation of the field of view was the major restricting factor, and a second opacification was necessary in two cases. One case with multiple renal arteries was unacceptable as the lowest renal artery was missed. Renal vein visualization by IADSA with renal artery injection was not reliable due to misregistration artifacts caused by bowel gas. Embolization with IADSA was satisfactory. Significant reductions in contrast load and procedure time were achieved. IADSA was found to be an effective tool in vascular mapping and embolization of renal tumors. Selective renal arteriography to visualize renal veins was better performed with conventional techniques.

Angiography↗

PubMedDate not supplied

Renal sinus varix: an additional differential diagnosis of a renal hilar mass.

Renal sinus varix of the left kidney in a patient with circumaortic left renal vein is described. CT appearance of the varix resembled parapelvic cyst except that the varix did not displace or stretch the collecting system. The venous phase of left renal arteriography disclosed its nature. Renal sinus varix should be added to the differential diagnoses of renal hilar mass.

Angiography↗

PubMedDate not supplied

Mesenteric varices: an entity with specific clinical, angiographic features.

Eight Japanese patients with mesenteric varices were diagnosed by angiography. All patients suffered from portal hypertension and had a history of previous abdominal surgery or peritonitis. The mesenteric varices of these patients were thought to be related to adhesion. Of the eight patients, five showed hepatic encephalopathy. None of the patients had a history of massive lower-gastrointestinal bleeding. All mesenteric varices were opacified in the portal phase of superior mesenteric arteriograms. To study the superior mesenteric artery, 50-60 ml of 76% Urografin was injected after infusion of prostaglandin E1 or F2 alpha. Regarding patients treated in the early part of the study, a vasodilator was not used and the contrast dosage was modest. In all eight patients, the mesenteric varices communicated with the systemic venous circulation through the gonadal veins. In seven cases, the mesenteric varices on the right side of the mesenteries drained into the right gonadal veins which flowed into the inferior vena cava (IVC). In the remaining case, the mesenteric varix on the left side drained into the left gonadal vein which flowed into the left renal vein. In three patients with right-sided varices, venous blood sampled from the right gonadal vein and from the distal and proximal IVC showed a high concentration of ammonia in the right gonadal vein and step-ups between distal and proximal IVC.

Adult↗

PubMedDate not supplied

Gelatin gel beads as an embolic agent.

Gelatin gel beads (GGB) is a compound of a long-chain polypeptide cross-linked with glutaraldehyde. It has been produced exclusively for embolic purposes. The object of the tests reported here was to determine the efficacy of GGB as an embolic agent in dogs as initial studies with rats had shown no acute toxic reaction. Eight dogs were used as subjects. Transcatheter embolization of one kidney in each animal was performed with a suspension of 500 mg of GGB and contrast material. The embolized kidneys were re-examined after one to five weeks. Embolized vessels remained occluded up to five weeks after the procedure. There was mild granulomatous reaction which started to organize at about the third week. The availability of GGB in various sizes when mixed in an isotonic solution makes it unique when compared with other forms of embolic agents. As this agent has now been shown to be a safe and reliable agent in dogs, it can now be used for testing in human subjects.

Animals↗